mcilhenny



(No Model.)

J. 1). MoILHENNY.

GAS VALVE. No. 542,024. Patented Julyp2, 1895.

d Eh \C WITNESSES INVENTCR UNITED STATES.

PATENT OFFICE.

JOHN D. MOILHENNY, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO A HELME & MCILHENNY, OF SAME PLACE.

GAS-VALVE.

SPECIFICATION forming part of Letters Patent No. 542,024, dated July 2, 1895.

Application filed November 17 1893- fierial No. 491,223. (No model.)

To all whom it may concern:

Be it known that I, JOHN DQMGTLHENNY, a citizen of the United States, residing in the city and county of Philadelphia and State of Pennsylvania, have invented an Improvement in Gas-Valves, of which the following is a specification.

My invention relates generally, although not restrictively, to apparatus employed in the distribution or transmission of natural gas from its source to the consumers.

Natural gas, as is well known, as taken from its source and transmitted to consumers by means of apparatus most commonly employed is subject to abrupt and more or less violent temporary increases in its pressure, and such as occasionally exceed the strength or resisting capacity of the meters and fixtures within buildings to which it is piped, with the result that widespread damage to such meters and fixtures is occasioned.

It is the object of my invention to provide for insertion in the circuit of a gas-pipe between its source of supply and the meter Within the residence of the consumer an inexpensive, simple, and efficient valve, which shall be so constructed and arranged as to be adapted to be automatically closed by the gaspressure when such pressure exceeds a predetermined limit arranged with relation to the known strength of the meter an d fixtures with in a building. j

A further object of my invention is to provide a gasvalve of the foregoingcharacter which, when thus automatically closed by the gas-pressure, shall remain in closed position even after the gas-pressure has been reduced to its normal strength and until the said valve is manually unseated or opened by the cod sumer the flow of gas to whose building has been thus interrupted.

In the drawings I show and herein I describe a'good form of a convenient embodiment of my invention, the particular subjectmatter claimed as novel being hereinafter definitely specified.

In the accompanying drawings, Figure 1 is a central vertical sectional elevational view of a valve-casing and valve embodying a good form of my invention. Fig. 2 is a similar view of a modified form of myinvention. Fig. 3 is a similar view of a valve head and stem, the said valve-head being shown as provided with a facing of yielding material.

Similar letters of reference indicate corre sponding parts.

In the drawings, A is a valve-casing containing the operative parts of my improved device, said casing being a tubular structure, the axis of the central portion of which is V61 tical and the extremities being shown as so bent and threaded as to be adapted to make connection, respectively, with two adjacent horizontal gas-pipes, (not shown,) between which the casing is placed and which it serves to unite.

The valve-casing is shown as made of three parts so rew-threaded together. This is a matter of convenience of construction merely, as it is to be understood that any desired general arrangement and mode of construction of my improved gas-valve may be resortedto.

Referring to Figs. 1 and 2, a is the gas-inlet I passage, and a the gas-outlet passage, said passages leading respectively to and from a valve-chamber B of considerably greater diameter than said passages. The outlet-pas sage a, which constitutes the eduction part of the valve, is slightly reamed out or enlarged at its mouth to form a valve-seat a Within the valve-chamber B is contained a free valve-head D, shown as of hemispherical form, supported by any suitable device, normally in open position, but free for vertical movement from its open position, which it is in Fig. 1 shown in full lines as occupying, to its closed position, which it is in said figure shown in dotted lines as occupying.

When the valve is in its lowermost position its base is immediately over and extends completely across the mouth of the inlet-passage, so as to be directly encountered by gas entering through said passage.

The valve-head, when elevated to the closed position shown in Fig. 1, is, by means of the mechanical expedients hereinafter described, adapted to be self-retaining in its seat, even after the force or pressure by which it has been elevated has diminished.

In the upper portion of the casing and immediately above the valve-seat a is formed an opening a ordinarily closed by a removable plug a, through which opening access may be had to the interior of the casing.

Suitable means for supporting the weight of the valve-head when it is in its lowermost or open position and for guiding it in its vertical movement being provided, the operation of the device will be readily understood.

The valve being supposed in its open position, as shown in Fig. 1, gas at any ordinary pressure entering the inlet-passage flows through the valve-chamber (the space between the edges of the valve-head and the walls of the valve-chamber being substantially equal to the transverse area of the gasinlet pipe) and out through the gas-oulet passage without disturbing the valve-head. When, however, the pressure of' the gas entering through the inlet-passage increases beyond that predetermined measure which the valve-head is able to resist undisturbed, it operates, acting against the fiat horizontal under surface of the valve-head, to carry or force said valve-head upward and into the valveseat a The valve-head, being self-sustaining, as described, thereupon remains in position in its said seat, completely shutting off the supply of gas to the pipe which is in communication with the gas-outlet passage.

As stated, the valve-head when closed remains closed, notwithstanding the reduction of the gas-pressure beneath it to its normal force, until manually unseated or opened by the consumer in whose building the valve is situated, and this is a desideratum, for the reason that the closing of the valve will extinguish any fires or lights in the building which may be in operation atthe time, and, should the valve after extinguishing such lights and fires automatically open and the gas resume its flow to the various open burners, the gas would, without the knowledge of the occupant, escape into the building, a condition attended by many dangers, both to the building and its occupants. In my construction, on the contrary, the fact that the valve remains closed will, when the room in which lights or fires thus extinguished are unoccupied, prevent that escape of gas thereinto which would be possible if the valve automatically opened upon the cessation of the extraordinary gas-pressure and will, by rendering it necessary for the consumer to open the valve, charge him with the responsibility of ascertaining that the open burners, the flow of gas to which he has restored, are either relighted or closed.

In the form of apparatus shown in the drawings the valve may be unseated by removing the plug a and forcing the valve down from its seat by any suitable inserted implement or tool. As soon as the valve is unseated it will drop by gravity to its open position.

In practice I prefer to providethe valve with a basal horizontal circumferential enlargement d, the diameter of which is considerably greater than that of the valve-head and valve-seat, and this circumferential enlargement affords a proportionately broader surface to be acted against by the gas entering through the inlet-passage than would be afforded by the base of the valve-head itself, whereby the sensitiveness of the valve to fluctuations in the force of the gas-pressure is increased.

'lhe'arrang'ement and operation described are common to both the forms of device illustrated, respectively, in Figs. 1 and 2.

The valve-head of Fig. 1,to which figure reference is now to be made, is rendered self-retaining by reason of the fact that the sides of the valve-seat and'valve-head are of such slight taper or slight inclination from the vertical that when said valve-head is elevated to the seat by the gas-pressure it becomes wedged therein and makes what may be termed a' jam fit of such tightness as to retain the valve-head in said seat. A cross-piece O, brid ing the central portion of the valvechambcr, limits the downward movement of the valvehead and serves to support said valve-head when thelatter is in open position. The valvehead is provided with a depending stem d, whichv works in an opening in the cross-piece C, and said stem and opening therefore serve to guide the movements of the valve-head.

In the form of the device shown in Fig. 2 the arrangement for rendering the valve selfretaining in its closed position is as follows: The valve-stem (l, as shown, exists and works within a vertical cylindrical chamber 61 open at its top, and suitably supported within the valve chamber by means of a spider (I and said valve stem is provided as to its lower extremity with an enlargement or washer d of flexible material of considerably greater normal diameter than the interior of the cylinder d When the valve-stem with its enlargement is forced into the chamber (1 the enlargement is necessarily compressed and will, when within the chamber, by its effort to reassume its normal set, take such a frictional hold upon the wall of the chamber as will retain itself, the valve-stem, and the valve, inany position to which they may be set, with sufficient strength to resist, when down or open, the tendency of the ordinary gaspressure to raise or close the valve, and when closed the tendency of the valve to descend by gravity. This being the case, when unusual gas-pressure exists behind the valve it will force said valve to closed position, and the frictional hold of the enlargement upon the wall of the chamber will retain said valve in closed position.

In the construction of Fig. 2 the valve-head and valve-seat are, similarly to the arrangement described with reference to the construction of Fig. 1, adapted to make a jam fit, but such jam fit is not necessary in said construction of Fig. 2 to render the valve-head self-retaining in closed position, as the described enlargement (i of its valve-stem acv complishes this result. a

The valve-head shown in detail in Fig. 3 is IIO shown as provided upon its hemispherical surface, which makes contact with a valve seat, with a facing E of yielding material, which may be of anyselected substance, such as leather or felt. The facing is shown in Fig. 3 as secured in position by means of a nut e, threaded upon a post d vertically eX tending above the top of'the valve-head, said nut being as to its under surface concave to match the hemispherical form of the valvehead.

The valve-head shown in Fig. 3 may beused in connection with either of the two constructions of valve shown respectively in Figs. 1 and 2.

Having thus described my invention, I claim-- 1. The combination, to form a gas valve, of a casing embodying a valve chamber, a gas inlet leading into the lower portion of the casing, and a gas outlet leading out from the upper portion of the casing, the mouth of the outlet being above and substantially in line with the mouth of the inlet and fashioned into a valve seat, a valve head existing free for vertical movement within the valve chamber and adapted to said valve seat, means for normally supporting said valve head across the mouth of but a slight distance above the mouth of the inlet and for guiding the vertical movement of the valve head, and means for retaining the valve head in the valve seat,- against the force of gravity and independently of fluid pressure, substantially as set forth.

2. The combination, to form a gas valve,of a casing embodying a valve chamber, a gas inlet leading into the lower portion of the mally supporting said valve head across the mouth of but a slight distance above the mouth of the inlet and for guiding the vertical movement of the valve head, the valve head and valve seat being so conformed that said head is adapted to make a jam fit within said seat and to be self-retaining in position against the force of gravity and independently of fluid pressure, substantially as set forth.

In testimony that I claim the foregoing as my invention I have hereunto signed my name this 16th day of November, A. D. 1893.

JNO. D. MGILHENNY.

In presence of- F. NORMAN DIXON, THOS. K. LANCASTER. 

